Related Experiment Video

Updated: Jun 13, 2026

A Behavioral Screen for Heat-Induced Seizures in Mouse Models of Epilepsy
06:58

A Behavioral Screen for Heat-Induced Seizures in Mouse Models of Epilepsy

Published on: July 12, 2021

Diurnal variation in febrile convulsions

Masaaki Ogihara1, Shuuichirou Shirakawa, Tasuku Miyajima

  • 1Department of Pediatrics, Tokyo Medical University, Tokyo, Japan. info@ogihara-cl.com

Pediatric Neurology
|May 18, 2010
PubMed

Insights

Febrile convulsions occur more frequently in the evening, mirroring body temperature patterns. However, circadian rhythms do not affect seizure severity, suggesting temperature set point elevation influences timing.

Area of Science:

  • Pediatrics
  • Neurology
  • Circadian Biology

Background:

  • Febrile convulsions are common in young children.
  • Understanding diurnal variations in febrile convulsions is crucial for clinical management.
  • Previous research has not fully elucidated the relationship between circadian rhythms and febrile convulsion occurrence and severity.

Purpose of the Study:

  • To determine diurnal variations in the occurrence of febrile convulsions.
  • To investigate if diurnal variations influence the severity of febrile convulsions.
  • To explore the relationship between body temperature patterns and febrile convulsion timing.

Main Methods:

  • Systematic data collection through witness interviews within one week of the event.
  • Study included 326 children aged 6 months to 6 years with simple febrile convulsions.
  • Analysis of convulsion frequency, timing, body temperature, and seizure duration.

Main Results:

  • Febrile convulsions were approximately 5 times more frequent in the evening than in the early morning.
  • Maximum occurrence peaked at 4:00 PM, minimum at 4:00 AM, aligning with body temperature circadian rhythm.
  • Seizure temperature and duration showed no significant difference between high-frequency (evening) and low-frequency (morning) periods.

Conclusions:

  • Circadian rhythm does not alter seizure propensity but influences the hourly occurrence of febrile convulsions.
  • Elevated temperature set point within the 24-hour period is likely responsible for the observed diurnal pattern.
  • Rectal administration of anticonvulsants during high-frequency periods may help prevent recurrent febrile convulsions.

More Related Videos

Behavioral Characterization of Pentylenetetrazole-induced Seizures: Moving Beyond the Racine Scale07:35

Behavioral Characterization of Pentylenetetrazole-induced Seizures: Moving Beyond the Racine Scale

Published on: July 8, 2025

Interictal High Frequency Oscillations Detected with Simultaneous Magnetoencephalography and Electroencephalography as Biomarker of Pediatric Epilepsy10:22

Interictal High Frequency Oscillations Detected with Simultaneous Magnetoencephalography and Electroencephalography as Biomarker of Pediatric Epilepsy

Published on: December 6, 2016

Related Concept Videos

Patterns of Fever01:26

Patterns of Fever

Before understanding the types and patterns of fever, it is essential to know its phases.
Increased Body Temperature01:25

Increased Body Temperature

A body temperature above  38°C  (100.4 °F) is known as fever or pyrexia, and a person with fever is termed 'febrile.' Typically, the hypothalamus, a part of the brain that acts as the body's thermostat, regulates body temperature through a thermoregulatory setpoint. It receives signals from cold and warm thermal receptors throughout the body and adjusts the body's temperature accordingly. Fever occurs when this hypothalamic setpoint is altered, usually in response to an infection or illness.
Types of Fever01:25

Types of Fever

Fever can be triggered by several factors, including infections, nervous system disorders, certain cancers, blood diseases like leukemia, embolism, thrombosis, heatstroke, dehydration, surgical trauma, crushing injuries, and allergic reactions.
Here are the different types of fever:
Seizures l: Introduction01:20

Seizures l: Introduction

Understanding seizures and epilepsy relies on key definitions that help in recognizing, classifying, and managing these disorders. These definitions provide a framework for recognizing, classifying, and managing seizure disorders.DefinitionsA seizure is a sudden, abnormal burst of electrical activity in the brain that can cause changes in awareness, movement, sensation, or behavior, depending on the area involved. Epilepsy is a chronic condition characterized by recurrent, unprovoked seizures,...
Seizures: Classification01:13

Seizures: Classification

Epilepsy is primarily characterized by unpredictable seizures, either provoked by an identifiable factor, such as injury or illness, or unprovoked, occurring spontaneously without apparent cause.
Seizures are typically classified into two main categories: focal and generalized seizures.
Focal Seizures
Focal seizures originate from specific regions of the brain. These seizures are further sub-classified into two types:
Seizures ll: Types01:19

Seizures ll: Types

Seizures are sudden bursts of abnormal electrical discharge in the brain that interfere with normal function. They are commonly divided into three groups: focal seizures, generalized seizures, and other types that do not fit neatly into either category.Focal SeizuresFocal seizures begin in a single brain region. When awareness is preserved, they are called focal aware seizures and may cause sensations such as tingling, unusual smells, or flashing lights. When awareness is impaired, they are...